SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4cdfce27bdd568f83c332d5bfda69d902be43495253bfca53313151201e9cd8a' 
  AND token = 'fTI+w5bkNdAZg2oSt27LRol1/gTRau6eHRXQQG8msdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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