SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea8d1f79f28d61440968aae4513b050830650b95085042bba4a00b392cc8ffc3' 
  AND token = 'WGxB1YR1TYKg7S0PEzcMQRDcJllkw+fgAdbKlFLFXu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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