SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a3df51130182bcbe48dead3f370c6c629836fcc0d57713c959c8f25774b4b9e' 
  AND token = 'm23BipEQyMiUee6YqabMoXbBqCNH9E7Hwzgy+WfdK8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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