SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7487322eef845f9bb545d09830a0f0c3664dc79f313f600be8271844f8138111' 
  AND token = 'XOLXFI59vMCvR03TRDaOAhZB0igmSUAEagUlPlv+qmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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