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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5e3cd4316c1e9b5f74c3ef24eefacb49faa3a11bbe2af6a054be37c0200bf32' 
  AND token = 'x1m2uavmLdFDtkHRhNTAnVDtejTiT3DDmZ6ROQfRBpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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