SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2752bb12a18aca1093573c3797fce19fa3247e088ca4b82a646c1484e2c857c1' 
  AND token = 'zeTl5t+ySfh3aiLpxB4gEsSOJ06sgsqw4kVjl1JgF8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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