SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0326bf200ba549eedeb246698a114aebebb18baa0f910cff0c7ba4033aa525a' 
  AND token = 'KqjZ+lERyxXrEter+wM5NjrcUp6/4LK7bqfQDY1+Htg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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