SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '786b7da57e458ea001d2c895e697b1f1e2cd3045635fe4d6f0b626101ff904ba' 
  AND token = 'JaloJFVi6cCHydbiFfFyMweaTSUaPZagPGkX0uFu69s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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