SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '842208ada479aa87425ce736eedc8716e72e2f6ebbcfa5c897ab019b0b43f0b3' 
  AND token = 'h9iw9IBOFJthqG0uBSBflmDqS4S9HoNM2px5JjGCC2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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