SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee0d7f758c168c4a17ac43f497e73a8d6adde8e49850c843aaac016af1ac7bb0' 
  AND token = 'Bb3g/GVrlO17rBvBEWoO2YGUiLFZ1kR7JtO4Is4Aay4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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