SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc7324688673a1bd6e0210ad5522d27b1bdc38aa34bfe651c025eb7a2b86ff9' 
  AND token = 'BDiZGThIqE3oBRH/CGiGavLGhLp/nQ2atEP3JLbvzKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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