SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab4e7f0f817d80607dfebefeac0c731c43b34aa961207671bf2218829e8b2b27' 
  AND token = 'M95reUZwnjzg7fm06mEHfFChkWBwkz1WvLiDr5BJiPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}