SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0508da585338b7fbc8168543d749d54a014ebb339ce625619ddb9dad895904e6' 
  AND token = 'oOy66K95XENypp2taJeyySvhBePbZQww5WBKjWKmB8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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