SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372a8092bb9f78d29b42dffc874eef1ddf765c27169b6b86c3dfeabef013b6f5' 
  AND token = '6rQVUKcW1/9CPcLeoCzuuERh893xVRKknummqnd9i80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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