SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7343eedff0cf431268fb38b04dfa8984135df1449540cd5f57ff487cc2a68940' 
  AND token = 'UOAiGpcA7YEtfX4w5aaqTtiuJM3Qpke0xH5X58/4e3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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