SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59bd7be86b618f4920594105f6d38f3cf68efbf5850c6c141f2ba8b29b7dde59' 
  AND token = '9cmaLoB0IFULzpeNGlEqVmYij2qSC4enHtrv5uvKNBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}