SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e4ea5d6a31acb79d8f8f9366a9fdba433a5cedcc4cb5ffe25716f791b23f46c' 
  AND token = 'LpFHEgroLmhjR4Q+ebj8T1DczMctLCI64FMGkNcGWPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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