SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612e43c64e6a56f1507f868fe48d0e1318a80445a2aaad168df0ec924f2ea62a' 
  AND token = '4Jl7OM+wknESfbaWUxtmG/fJQ+qamrQSgUQHTurJM1w=' 
  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"
    }
  }
}