SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb53a94733adedbb98325befacc8cab48246115c24ea3a06b82b5aa33b78cdbb' 
  AND token = 'ar+jtGhsPudRNj+9mfn9qwXrqt6Zhaevc4AD+qBO0l0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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