SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36db7aa1c1db83d99030d42b0a88f16850a6858be209e2fdca1334f9015e902b' 
  AND token = '4fy8MuaMB+1dRI3P7A2hYhJ5TjybBuMiljqjjcrjpT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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