SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ef1e7cf2acd0ddca3eb303315670ae5ea7d66b42f50aff1ba2cfdafdefc8937' 
  AND token = 'w2A9n0l1jy914/kwIKbj9HWowdMFyu3VOY8wUHuMzoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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